C'mon Digimon/YMMV

Complete Monster: Shinichiro Josaki is a vicious bully obsessed with being the strongest Digimon Tamer in the world. As the spoiled heir to Josaki Industries, Shinichiro uses his resources to create the powerful Deathmon, to force children to use their pet-like Digimon to duel him under threat of physical violence. After invariably defeating the children's Digimon, Shinichiro gleefully destroys the Digimon just to torment them before moving on to his next victim. Shinichiro always studies up on his coming opponents so as to learn past traumas or fears and use those to further torture them for his own entertainment, notably trying to burn Kentarou's Digimon alive after learning that Ken once had a pet dog who'd died in a fire. Shinichiro was the first Digimon villain ever created, and still stands out as one of the franchise's most petty and cruel.
The Woobie: Makoto, who has V-Pets because his parents don't allow pets and he keeps a diary for them all as though they were real. Then Shinichiro crushes one of his V-Pets...